Macadamia ternifolia

The Australian Botanic Garden, Mount Annan - September

Genus:Macadamia - named after John Macadam, a colleague of botanist Ferdinand von Mueller, who first described the genus.

Species:ternifolia - from Latin, ternarius, consisting of threes; referring to the leaves in whorls of three.

Distribution

Endemic to southern coastal Queensland, with a known national distribution of scattered populations extending from Goomboorian south to the Pine River.

Native habitat

Occurs within lowland rainforest in higher rainfall areas where it is scattered in small clusters within the forest.

Description

Small, mulit-stemmed subtropical rainforest tree to 6 m tall.

Flowering/fruiting

Flowering has been recorded from June to October with fruits from December to March.

Location in Garden

One plant in Bed 16 in the Connections Garden.

Information

This is a rare species, which is federally listed as Vulnerable. The total population size in the wild is estimated to be between 1000-2000 mature individuals with approximately 20 key populations with around 5-20 mature specimens at each locality.

Threats include clearing for agriculture and urban development (especially critical habitat linkages such as riverine corridors), inappropriate fire regimes, weed invasion and loss of genetic viability due to a lack of connectivity between populations and a lack of pollinators and dispersers. Very little is known about the life history and ecology of this species. Both introduced European honey and native bees appear to be the main pollinators, with native social bees (Trigona spp.) being superior pollinators.

Seed dispersal is by small rodents and gravity fall, probably with some assistance from local stream flooding. The new flushes of growth make this an attractive species, however the kernel is cyanogenic (generating cyanide), i.e. bitter and poisonous.